188434-15-3Relevant articles and documents
Unusual reactions of methylsulfonyl esters: Syntheses of 3α-methyl and 3β-methyl gibberellin A20
Beale, Michael H.,Loaring, Huw,Peakman, Torren,Penny, Martin,Willis, Christine L.
, p. 433 - 442 (1997)
Gibberellin A3 has been converted to 3α-methylGA20 8 in 33% yield via catalytic hydrogenation of the 3-exo-methylene derivative 14. In an attempt to prepare 3β-methylGA20 9, the 3α-methanesulfonate 25 has been treated with lithium dimethylcuprate; only the β-keto sultones 26 and 27 have been isolated (84% yield). In contrast, under similar conditions the 3α-methanesulfonate 35 gave the 2-oxopropylsulfonyloxy derivatives 36 and 37. Synthesis of 3β-methylGA20 has been achieved via reaction of the 3α-trifluoromethane-sulfonate 38 with lithium dimethylcuprate. 3α-MethylGA20 and 3β-methylGA20 show similar activity to GA20 (and significantly less activity than GA3) in the stimulation of stem elongation of dwarf rice seedlings.